Calculating machine



April 12, 1938. c. CAMPBELL CALCULATING MACHINE Filed Jan. 10, 1934 13 Sheets-Sheet l INVENTOR% A T RNEY April 12, 1938. QICAMPBELL 2,113,612

CALQULAT ING MACHINE Filed Jan. 10, 1934 13 Sheets-Sheet 2 INVENTOR ATTOBNEY April 12,- 1938. c. CAMPBELL CALCULATING MACHINE Filed Jan. 10, 1934 13 Sheets-Sheet 3 'INVENTOR 4 A TO N Y April 12, 1938. Q CAMPBELL I 2,113,612

CALCULATING MACHINE Filed Jan. 10, 1934 l3 Sheets-Sheet 5 .//so are m /894 mm/ m 1/ J /69 INVENTOR ATTORNEY April c. CAMPBELL 2,113,612

CALCULATING MACHINE Filed Jan. 10, 1934 13 Sheets-Sheet 6 -INVENTOR M ATTORNEY W 11/7/29 will: tens April 12, 1938. Q CAMPBELL 2,113,612

' CALCULATING MACHINE Filed Jan. 10, 1934 1:5 Sheets-Sheet '7 FIG.3

INVENTOR ATTORNEY April 1938. c. CAMPBELL 2,113,612

CALCULATING MACHINE Filed Jan. 10, 1934 13 Sheets-Sheet 8 cst-I.

CS Z 74 CSm-I FIGQQ.

INVENTOR %M 1 ATTORNEY April 12, 1938. c CAMPBELL 2,113,612

CALCULATING MACHINE Filed Jan. 10, 1934 13 Sheets-Sheet 9 9 Lf/ROI FIG. 3

INVENTOR Ai TORNEY A ril 12, 1938. c. CAMPBELL CALCULATING MACHINE Filed Jan. 10, 1934 13 Sheets-Sheet 10 HwHwHwHwHwHwHww INVENTOR ATTORNEY FIG. 33.

April 12, 1938. c. CAMPBELL CALCULATING MACHINE Filed Jan. 1.0, 1934 13 Sheets-Sheet ll INVENTOR A RNEY April 12, 1938.

c. CAMPBELL 2,113,612

CALCULATING MACHINE Filed Jan. 10, 1954' 13 Sheets-Sheet 13 Ark/m4 new cnrs 'INVENTOR ATTORNEY lil Patented Apr. 12, 1938 PATENT OFFICE 3,113,612 CALCULATING mourns Charles Campbell, London, England, alsignor to International Business Machines Corporation, New York. N. Y., a corporation of New York Application January 10, 1934, Serial No. 'i06,l0d In Great Britain January 13, 1933 9 Claims. (CI. 29.5-61.6)

This invention relates to calculating machines for performing calculations involving amounts expressed in terms of a non-uniform notation, such, for example, as amounts expressed in terms of pounds, shillings, and pence.

By the term uniform notation" is meant a notation such as the decimal notation, having a single base common to all the denominations of an amount and by the term "non-uniform notation" is meant a notation having more than one base each of which is related to a particular denomination or denominations.

In certain kinds of calculations, in particular multiplication, the calculation and/or the mechanism required to perform it may be greatly simplified by taking advantage of the fact that an amount expressed in terms of a uniform notation can be multiplied or divided by the base of the notation by altering the position of the decimal point. Such an alteration will be referred to hereinafter as a column shift operation and is not possible when an amount expressed in terms of a non-uniform notation is involved.

It has been proposed to provide translating mechanism ,for converting an amount expressed in pounds, shillings and pence into terms of pounds and decimals of a pound and also to provide translating mechanism for effecting the converse operation. An amount expressed in terms of pounds, shillings and pence cannot, in general, be expressed exactly as decimals of a pound so that a small error will be made during the conversion. If the amount is tobe multiplied, the decimalization must be carried far enough to ensure that the error is negligible. Thus if a sterling amount is to be multiplied by an eight figure number, the decimilization must be carried to eleven figures of decimals at least or to twelve figures if the product is obtained as the sum of a plurality of partial products or to thirteen or fourteen figures, if a series of decimal products are to be added together to form an accurate sum. This involves complicated translating mechanism and necessitating larger'capaca feature of the invention to arrange the translating mechanism to effect the conversion of the first of the amounts forming the sum or difference into the said uniform notation. Thus, when the amount entered. is in pounds, shillings and pounds, shillings and quarter-shillings and a remainder of one penny.

It is a feature of this invention to provide a multiplying machine comprising in combination means for entering two factors to be-multiplied together of which one is expressed in a non-uniform notation; translating mechanism for converting the said factor into the sum or difference of an amount expressed in a uniform notation and a remainder, multiplying mechanism for obtaining the product of the amount in the uniform notation and the otherfactor, additional multiplying mechanism for obtaining the product ofthe remainder and the other factor, means for translating one of the products into the notation of the other and means for obtaining the sum or difference of the two products. Conveniently, the two products are obtained each in a separate accumulator and there is provided means for reading the uniform product out of its 8.0- cumulator, and entering it into the other accumulator, which means constitutes a re-translating means so that the uniform product is converted into terms of the non-uniform notation and added to the other product in one operation.

When the non-uniform amount is expressed in terms of pounds, shillings and pence, the conversion is preferably, as explained above, into a decimal amount and the remainder of one penny or twopence. The additional multiplying mechanism preferably includes means operable when the remainder is either one penny or twopence, to express the product of the appropriate factor and one penny in terms of pounds, shillings and pence, and means operable to add the product thus obtained to itself when the remainder is twopence. The entering means may be constituted by a device for reading perforated records. The reading device may be of the kind in which the records are read while in motion and impulses are generated at times representative of the amounts read from the record and the pulse distributor I55.

translating mechanism may beadiustable by impulses transmitted to it from the-reading device and operable to emit impulses timed to represent at least a portion, for example the decimal portion, of the converted uniform amount and the remainder.

The above described process of converting an amount expressed in a non-uniform notation into the sum or difference of two amounts is appiicable to calculating machines other than multiplying machines. It may, for example, be applied, with advantage in certain cases, to means for translating an amount in a non-uniform notation into an amount in the decimal notation, by converting the amount into an amount accurately expressed in the decimal notation and a remainder which is separately converted, to the desired degree of accuracy, into the decimal n'otation, and then adding together the two amounts so obtained.

A record-card controlled multiplying machine embodying the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:-

Figures 1 and lashow diagrammatically various parts of the machine and the drive to those p Figure 2 is a section through card-feeding and reading mechanism of the machine;

Figures 3a to 3h arranged from left to right in that order, form a circuit diagram for the machine;

Figures 4 and 4a are a timing diagram for the machine, and

Figure 5 shows diagrammatically, an electromagnetic relay in the machine.

Like reference numerals indicate like parts in General arrangement Referring first to Figures 1 and 1a the machine is driven by a motor M, which, through a belt drive 9 drives a shaft 5| which in turn drives an A. C'., D. C. generator 52. This generator supplies both A. C. current and D. 0. current to the various circuits of the machine. The shaft 5|, through worm gearing II, drives a vertical shaft 54 which, through worm. gearing 55, drives a shaft 58. The shaft I! drives three accumulators, FP, LH and RH. The shaft 56 also drives a group of seven emitters, EMI to EMI, a group of cams CCI to CCI, and an im- The emitters are constituted by electric commutators, and provide timed impulses for operating various circuits. The cams operate pairs of contacts which are also designated CCI to CCI, and operate constantly so long as the machine is in operation.

The shaft SI carries a gear wheel 51 which meshes with a gear wheel 58. This gear wheel through Geneva gearing 59, 8!, drives a gear wheel I having internal teeth. A gear wheel 62 meshes with the gear wheel I and is secured on a reset shaft SI. Each of the accumulators FP, LH and RH can be coupled to the reset shaft on the engagement of a separate and associated one-revolution clutch, N, which is engaged on the energization of an electromagnet 1| FP, ll L1! or II RH, respectively. When one of the clutches is engaged, the corresponding accumulater is reset to zero in the known manner.

A cam H is secured to the driven member of the clutch N of the accumulator LB, so that this cam turns through one revolution whenever the accumulator L8 is being set. This cam opens a pair of contacts LIL-4 and closes two pairs of contacts LH-b and LH-c, and also a pair of contacts LH-d (not shown).

The driven member of the clutch N for the accumulator FP carries a similar cam Ha which rotates when the accumulator is reset and closes a pair of contacts FP--a.

In the lower part of the machine are two accumulators constituting a multiplier register MP and a multiplicand register MC. These accumulators are driven from the shaft 54 in a manner similar to the upper accumulators, and the driving connections are given similar references but with the suffix at. These two registers may be reset on the energization of reset magnets II M? and 10 MC. The driven member of the clutch Na for the register MC carries a cam 12 which rotates when the register is reset and opens a pair of contacts MfJ-b and closes a pair of contacts MC--a.

A number of multiplying relays are provided in a unit MPH. and a number of column-shift relays are provided in a unit CS. All these relays are structurally similar to the multiplying relays described in the above mentioned patent, and include a controlling magnet which when energized at the beginning of a cycle of the machine, renders the relay operative. Each operative relay is mechanically restored to its normal condition at the end'of the cycle in which it became operative. The mechanical movement of the relays are actuated by two cams 65 and 65b secured on the shaft 56a.

Card-feeding mechanism The shaft 56 carries a gear wheel 68 (Figure 1a) 'which, through gearing i9, drives a gear wheel 13 which is freely mounted on a shaft 15. The gear wheel 13, through gearing 1!, drives two gear wheels 8| which are secured to two pairs of feed rolls 82. These feed rolls thus operate continuously. The gear wheel 11 also drives a gear wheel 83 which is secured to feed-rolls l5, and the latter also operate continuously. One element 16 of a one-revolution clutch is secured to the gear wheel 13, and the other element ll of this clutch, which element is constituted by a pawl, is pivoted on an arm 18 secured to the shaft 15. This clutch is of a conventional onerevolution kind, and is engaged when a magnet I is energized and becomes disengaged on the completion of a revolution if the magnet I66 is de-energized at that time. The gearing i9 is such that one revolution of the shaft occurs while the shaft 56 is completing two revolutions. The shaft 15 carries a gear wheel Ha which drives a gear wheel "b. This gear wheel is secured to a gear wheel "c which drives a gear wheel 14d. secured to a conducting feed-roll IT. The roll I! thus revolves only so long as the card-feed clutch is engaged and co-operates with a plurality of card-reading brushes I09 (Figure 2). The gearing Ila to lid is such that the roll I! rotates at a slightly different speed to the shaft 15 in order that contact between it and the brushes I, through corresponding holes in the card, shall not always take place at the same spots on the roll. This reduces the liability for the roll to become pitted. Feed rolls 94 and 95 co-operate with the roll I! and are secured respectively to gear-wheels 1s and st (ms 1a),which ass with the gear wheel ll secured on the shaftJl. Thegearwheelilalsodrivesaseriesofcams ICJ to F0. through gearing ll. operate similarly designated contacts during card-feed cycles only.

The shaft ll carries a cam II which operates a follower "to rock ashaft Ill. This shaft carries an arcuate rack I which meshes with ing cycle, and feeds the lowermost card of the associated punch-selecting magnet H3 (Figure pile ill to the constantly-rotating feed-rolls 02. These rolls advance the card between the contact roll 01 and the feed-roll ll. At the end of the ilrst card-feeding cycle the card is clear of the rolls II and its leading edge is located between the brush ill and the contact-roll 01. In this position the card closes the card-lever contact III.

on the next card-feeding cycle, the card is fed pa t the brushes It! and the amounts contained in the card are read out and entered into the machine. This reading operation occurs during the first half of a card-feeding cycle. Finally the card is fed by the rolls 85 into a card-receiving tray of a punching mechanism. This position of the card is indicated at R in Figure 1a and in this position thecard 'closes card-lever contacts I". It should be noted that while one card is being fed past brushes Iii! and delivered to the punching mechanism, another card is being fed from the stack III into position to close the contacts H2, and with its leading edge beneath the brushes I09.

The punching mechanism The punching mechanism is identical with that described in the patent specification referred to above, and is of the kind described in the Lee and Phillips United States Patent No. 1,772,186. It will therefore be unnecessary to describe this mechanism in detail, and it will be sufhcient to state that, after each card has been fed to the position R (Figure In) it is fed to the left by a feed-rack III] which delivers it to a second feedrack not shown. The second feed-rack feeds the card further to the left until the first column of 'a held in which a product is being punched is beneath a row of punches. not shown. There are twelve punches. one for each hole-position in the 80). When one of these magnets is energized it closes contacts Iii (Figure 3h) to energize a punch-operating magnet II! which forces the selected punch through a card in the known manner. Concurrently, the second feed-rack escapes one step and brings the next column beneath the punching mechanism. 0n conclusion of-a punching operation the second feed-rack escapes continuously and brings the card into register with an ejecting mechanism. This mechanism is brought into action on the energization of ejector clutch-magnet III is energised and engages a clutch (not shown) to couple both the card-feed rackstoamoi'orm andalsoclosescontacts III to energise the motor 111. This motor then moves theiirstcard-rackwiththe newcardinitfrom right to left, and the second card-rack fromleft t0 right-so that the card is transferred from the formerto the latter. It should he noted that when a card has been positioned under the punches in readiness for punching, it remains in that position until a multiplying operation has been completed.

The various circuits involved in the'above operation of punching and electing the card. will be referred to again later.

General operation Before explaining the circuits of the machine in detail, a general explanation will be given of the manner in which the machine multiplier. 11 sterling amount by a decimal amount. It will be assumed that a card is passing through the machine which carries the two factors l2.l7.5 and 603. The calculations performed by the machine been removedfromthesecondcard-rachapimdi to obtain the product of these two factors are shown in Table I below:-

Tlisu: I

From card to multiplier register one From card to multiplicand register 1 From card to translator 17/5 2 m From translator to multiplicand register 0. 8625 From translator to pence relays 2d.

Multiplier Multiplicand LH partial product RH partial product Referringto this table, as the card passes the brushes I, the multiplier"! is read from the card. and entered into the multiplier register MP. Concurrently the pounds portion oi the multiplicand, namely, 12 is read and entered into the 5th and 6th denomination of the multiplicand register. The shillings and pence portion of the multiplicand, in this case 17/5, is entered into translating mechanism which is constituted by a number of relays described hereinafter. The translating mechanism determines that the amount 17/5 can be expressed as the sum of 17/3+2d. and it registers the remainder 2d. in suitable relays. All these operations have occurred during the first half'of a card-reading cycle. During the'second half of this cycle, the translating mechanism eniersinto the four lower denominations of the multiplicand register. the amount of 0.8625, which is the decimal equivalent in terms of pounds, with one pound as unity, of 17/5. These operations are shown in the upper part of the table.

The machine then proceeds to multiply the decimal pounds amount by 3, to obtain two partial products, one of which is entered into the accumulator LH, and the other into the accumulator RH. The next operation is to multiply the decimal pounds amount by 600, and enter the two partial products into the two accumulators LH' and RH. This completes the actual multiplying operation, and the machine next transfers the amount in the accumulator RH to the accumulator LH, to obtain a product of $7756.0875. These operations are shown in the center part of the table.

Concurrently with the above multiplying operation, the machine first determines the product 1d. 3, and then the product of 1d. 600, expressing the product, in each case, in the sterling notation. These two products are entered consecutively into the accumulator FP, so that this accumulator will eventually contain 210.13 the product of 1d. and 603. -The amount required, is, however, the product of 2d. and the multiplier; and accordingly, the amount in the accumulator FF is read out and reentered into the accumulator so as to be added to itself, giving a remainder partial-product of 5.05. If the remainder had been ld., instead of 2d., the doubling operation would have been omitted, while if there had been no remainder, no pence multiplication would have taken place.

The machine now contains 7756.0875 in the accumulator LH and 25.0.6 in the pence product accumulator. The former amount is read out and entered into the accumulator FP, being converted into the sterling notation during this operation, so that 7756.1.9 is entered into the accumulator FP, to get the final product of 7'76L2-3. The final operation is to punch this product and this is effected by the punching mechanism under the control of the accumulator The circuit diagram Before describing the operation of the machine with reference to the circuit diagram it should be explained that the three accumulators and two registers of the machine are conventional accumulators of the Hollerith type. The two registers comprise eight denominations each, and the accumulators RH fifteen denominations, and the accumulators LH and FF sixteen denominations each. The registers MC and MP and the accumulators LH and RH are arranged to register decimal amounts but the accumulator FF is a sterling accumulator arranged to register pounds,

shillings, and pence. An accumulator-magnet is provided for each denomination, these accumulator-magnets being designated l2l with a sufilx identifying them with the respective register or accumulator. For example, the accumulatormagnets for the register MP are shown at 121MP, Figure 34. Each magnet when energized couples an accumulator-wheel to a constantly rotating shaft, so that the accumulator-wheel turns toan extent determined by the time in the machine cycle when the magnet was energized, which time is in turn determined by the digit to be entered.

Each register and accumulator is provided with reading-out mechanism of a known commutator type. The reading-out mechanism MPRO (Figure 341) for the register MP will be explained briefly as being typical of them all. This mechanism includes a brush I224 for each denomina tion, each brush being driven by the associated accumulator-wheel. Each brush co-operates with a set of ten segments Illa and a common sector I2, and is positioned by its accumulatorwheel to connect one of the segments I234 to the segment I24a. Each segment Ina is allocated to a different digit, and the brush Illa engages the segment allocated to the digit registered by the corresponding accumulator-wheel. It will be seen from Figure 3a that certain of the sets of the segments I284 are common to two denominations. Each accumulator-wheel also drives a brush [22b which cooperates with a single zero segment ms and a common segment Iflb. The parts identified by the sufiix b form a separate reading-out mechanism for determining which of the denominations of the register contain zero, and controlling the cycles of the machine accordingly. The brushes I210 and H21) are shown in the position assumed when the amount 603 is registered in the register MP.

The reading-out mechanism MCRO for the register MC is shown in Figure 3e, and comprises two sets of reading-out commutators, similar to the commutators identified by the suffix a in the multiplier reading-out mechanism MPRO. This arrangement allows of two distinct series of circuits being completed through this reading-out mechanism, for the transmission of the two partial products of the decimal multiplication. The reading-out mechanism RHRO for the accumulator RH is shown in the same figure, and comprises but a single set of commutators. The accumulator LH has a reading-out mechanism LHROI (Figure 3!) for reading out the amount contained in that accumulator into the accumulator FF, and a second reading-out mechanism LHRO2 (Figure 39) which allows of the product being recorded from this accumulator when purely decimal multiplication is effected; The accumulator FP has reading-out mechanism FPRO which includes two sets of commutators, one to control the doubling operation, and the other to control the punching of the product. The manner in which these various reading-out mechanisms are wired up will be clear from the subsequent explanation of the circuit diagram.

In addition to the relays contained in the units MPR and CS, the machine is provided with a number of multl-contact electrical relays, which are identified in the circuit diagram by the reference RX and a sufiix or RC8 and a sufiix, RC, DC, D, and DT, and which control the multiplication of the remainder. shown diagrammatically in Figure 5. Each relay comprises an operating magnet RX or RG8 which, when energized, attracts its armature I25. This armature is then latched in its attracted position by a spring-pressed latch I28. When the armature is attracted it moves a contact-operating member I21 to the right so as to close a number of pairs of contacts I2l. To restore the relay to its normal condition, a resetting magnet RXa or RCSa is energized, and attracts the latch I2 so as to release the armature I25. A spring I2! then moves the contact-operating member I 21. and the armature I25 back to their normal positions. In the circuit diagram the operating magnet of each of these relays has the same reference as the relay, the resetting magnet has this reference and the suffix 0" and the contacts of the relay have this same reference with, in some cases, a numerical sufilx. The various relays RX and RC8 are distinguished from one another by suiiixes.

One of these relays isagain closing the contacts m.

card-feeding cycle the card has closed the con- Card-Iced and control circuits With the motor M in operation, the generator I! will supply direct current to lines I and III (Figure 3h) while the A. C. generator will supply alternating current to a wire I12 (Figure 3a) and to earth.

The machine is started by depressing a start key, I33 (Figure 3h) completing a circuit from the line I, through a relay coil C, the contacts- I, normally closed contacts GI and. cam contacts FC-Z. The coil C closes its contacts CI to complete a holding circuit through these contacts and cam contacts FC-l. This coil also closes contacts CI to provide a circuit from the line Ill through normally closed contacts FI, the card-teed clutch-magnet I", cam contacts l'C-l, stop contacts I, normally closed relay contacts NI, the contacts C2 and contacts PI, which are. closed by the card-rack Illl (Figure is) when this rack is in position to receive a card from the card-feeding mechanism. The contacts P-I ensure that the card will not be fed unless the punch is ready to receive it. After the cardfeeding mechanism has started in operation, the cam contacts FC-l open to de-energize the magnet C which in turn de-energizes the clutch magnet I. The mechanism will therefore come to rest after one card-feeding cycle, and with the first card with its leading edge just beneath the brushes I09.

A fresh card-teed cycle is then initiated by tacts III, which energize relay coils H and Q. The relay Q closes contacts Q-I (Figure 3a) to prepare the card-reading circuit. Early in the second card-feeding cycle, cam contacts FC-II (Fig. 3h) close to complete a circuit through contacts III and a relay coil G. The coil G opens its contacts GI to interrupt the starting circuit through the contacts Ill, and closes its contacts 6-! and 6-4 to provide a holding circuit extending through the contacts (1-) and cam contacts F'C-Z. This circuit is interrupted towards the end oi each card-feed cycle by the opening of the contacts FC-2, but the coil G is maintained energized over a circuit extending through the contacts G-2, G3 and H2 at the time when the contact FC--2 opens, provided that a card has been fed from the magazine and has closed the contacts II2. Thus so long as cards feed, either the contacts H2 or the contacts A typical circuit for entering the multiplier extends from the line I3I (Figure 3a) through the relay contacts Ql which are now closed, cam contacts FC-l which close during the reading portion of the cycle, the impulse distributor I" which prevents sparking at the brushes, the conducting roll 81, one of the brushes IMMP and the connected magnet IIIMP, to a line I30. These circuits are so timed by the holes in the card that the multiplier is entered into the multiplier register.

The present machine is capable of dealing with multiplicands containing four denominations of pounds, two of shillings, and one 01! pence. Brushes IIIOMC which read the pounds amount During the first from the card, are connected to the tour higher accumulator magnets IlIMC (Fig. 8b) of the multiplicand register by plug connections inserted between sockets I and sockets I". The circuits i'or entering the pounds portion 01 the multiplicand are similar to those by which the multiplier is entered.

The brush IllMC which reads the pence amount on the card is plug-connected to a socket I" (Fig. 34) while the brushes reading the shillings amount are plug-connected to sockets III and I38. As explained previously, the shillings and pence portion of the multiplicand is divided into an amount which is a whole multiple of three pence and a remainder oi nothing, one penny or two pence. The manner in which the remainder is determined and registered will now be explained.

Cam contacts FC-Il close momentarily while 7 energization oi! the relay 2R. In the same way,-

cam contacts FC-IO close momentarily while each of the hole positions 10, 'I, 4, l are passing the pence brush, and a relay IR will be energized to reglsterthe remainder 1d. If a hole had been punched in one of the 9, 6, 3 and 0 positions, neither Of these two relays would have been energized, and the machine would operate on the assumption that there was no remainder. It may be mentioned that 10 pence is indicated on the card by a perforation in the well known 11" or X" index point position and 11 pence by a perioration in the 12" or R" index point position. The uppermost line in Fig. 4 indicates the relationship between the time of sensing the values on the card and the points of the machine time.

Each of the relays 2B and IR closes, when energized, associated holding contacts 2R-I or IRr-I, to provide a holding circuit extending from the line I3I through the contacts Q-I, cam contacts FC-29, a line I40, the contacts 2R-I or IR-I as the case may be, and the associated relay coil, to the line I30. This holding circuit, is maintained until the card has been completely read, then cam contacts CC close to complete a circuit from the'AC line I32 through the closed contacts 2R-2 or IR-I and remainder control relay magnets RC. If the relay IR is energized, a circuit is also completed through the contacts 004, contacts 212,-; of the relay 2B and a doubling control relay magnet DC. The relays DC and RC are of the type shown in Figure 5, and the magnets just referred to are equivalent to the operating magnets RX shown in that figure. These relays remain operative during the whole of the calculating cycles of the machine, and are restored to their normal condition in a manner which will be explained later.

The remaining portion of the shillings and pence part of the multiplicand is read, translated into decimals of 1, and the decimal amount is entered into-the four lower denominations of the multiplicand register. The manner in which the translation is eifected will be clearer with the assistance of the following table which shows the decimal values for various shillings values plus 0d, plus 3d., plus 6d., and plus 9d.

From the above table, it will be seen that the value in the last two decimal places is either 00, 25, or 75, depending solely on whether the pence value were nothing, 3d., 6d., or 9d. respectively. Referring to Figure 30, four relays ID, 3D, 6D and 9D are provided, and correspond respectively to remainders of 0d., 3d., 6d., and 9d. The relay 0D must be energized when the pence digit is 0d., id., or 2d. and this relay is therefore connected to the lower brushes through cam contacts FG-li which are timed to close while the hole positions 0, 1 and 2 are passing the pence brush IOSMC so that the relay lD will be energized when there is a hole in one of these positions. The relays 3D and 6D are connected in a similar manner to the pence brush through cam contacts FC-IS and FC respectively; these contacts close respectively while the hole positions 3, 4 and 5 and the hole positions 6, 7 and 8 are passing the pence brush. The relay 9D is connected to the pence brush through cam contacts FC-Jl which close while the 9 hole is passing the pence brush, and cam contacts FC-ll which close while the 10 and 11 holes are passing the pence brush. The timing of these cams is shown in Figure 4, together with the time at which the various holes pass the brushes, the latter being shown in the top line on the left of this figure. When energized each of these relays closes contacts BD-I, 3D-I, 6Dl or SD-l, to provide a holding circuit for itself through cam contacts FC-28 which maintain the relay energized until late in the second machine cycle of the two such cycles comprised within a card-feeding cycle.

In Figure 3b the dotted line I indicates the division between the decimal and the pounds part of the multipiicand register, the magnets above this line being those which control the entry of the decimal amount. The plug-socket I35 connected to the lowest denominational magnet IIIMC is connected to a plug socket I which in turn is connected to a common segment N2 of the emitter EM (Fig. 3a). The emitters are all similar, and a brief description of this one will apply to all of them. The emitter EMI includes a pair of connected brushes HI which rotate synchronously with the cycle of the machine, to connect each of a number oi conducting segments Ill in turn to the common segment I42. Each of the segments 3 is associated with a separate digit and is connected in circuit at a time in the cycle appropriate to that digit. The "live" segment of this emitter is connected to a line 5, and the circuit through this emitter serves to energize the magnet IIIMC tor the lowest denomination at the "iive time in the cycle to enter 5, when the pence digit is either 3d., id. or 5d., or is 9d., 10d. or lid. From the line ill the entering circuit normally extends through relay contacts 'D-l, a line I, relay contacts lD-I, a line I", cam contacts FC-fl which close during the entering portion of the second machine cycle comprised within a card-feeding cycle, a line Ill and the relay contacts Q-I. It will be seen that this circuit will not be broken it either of the relays 8D and ID is energised, but will be interrupted it either or the relays ID and D is energized. In the latter case there will be no entry into the lowest denomination of the multipiicand register; in the former case 5 will be entered into the register. From Table II it will be seen that the entries should be made in this manner.

The second lowest accumulator-magnet IIIMC is plug-connected to the emitter EMU, the "two". live, and "seven digital conducting segments of which are connected respectively to lines Ill,

Ill and III. This allows oi the entry or either 2, 5 or 7 into this denomination of the register.

When ninepence is to be decimalized, the relay .D is energized, closes its contacts lD-2 completing a circuit through the contacts Q-|, the line I, the contacts FC-JI, the line I", the contacts ID2, the contacts lD-I, the line I, a line III, the contacts ID-I, a line III, the contacts lD-2 which have now been closed, the line Hi, the emitter EMU at the seven time in the cycle, and the accumulator-magnet IHMC for the lowest denomination but one. It will be noted that this circuit will be interrupted by the concurrent energization oi one of the other three relays. This is a safety measure.

When the relay CD is energized, the circuit extends as beiore, through the contacts ID2, the line I, and then through the now closed contacts lD-4, the line iii, the emitter EMU at the five" time in the cycle, and the accumulatormagnet IIIMC. In this manner 5 is entered when sixpence is decimalized.

When the relay 3D is energized, the circuit extends through the contacts liD-J, the contacts SD-I, the line I", the line in and the nowclosed contacts 3D-3, the line I, the emitter EMS, at the "two time in the cycle, and the accumulator-magnet in question. 2 is thus entered when threepence is decimalized. When there is no penma digit to be decimalized. the relay DD is energized, and opens its contact lD-I, thereby interrupting all the circuits through the emitter EMS so that no entry is made into the lowest but one denomination of the multiplicand register.

It will be seen from Table II that the digit in the second decimal place depends both on the pence value and on whether the shillings value is even or odd. Thus, with 0d. the value to be entered is 0 if the shillings value is even, and 5 ii the shillings value is odd. In the same way, with 3d., 1 must be entered if the shillings value is even and 6 if the shillings value is odd. In the same way, with 6d., 2 and 7 must be entered, and with 9d. 3 or 8 must be entered.

The units of shillings brush USMC is connected by the plug socket I31, to two pairs oi contacts FC-2B and FC-2i. The former contacts close momentarily while each of the odd-number hole positions is passing the brushes, while the latter contacts close momentarily while each of the even-number hole positions is passing the brushes. Thus, an entering circuit will be completed through the contacts I'O-Il and relays 08 if the unit at the shillings digit is odd and through the contacts FC-Ii and relays ES ii the unit of the shillings digit is even. The relay '8 or E8, as the case may be, closes holding contacts lS-l or ES-i to complete a holding circuit be interrupted by the open contacts 8-2. If,

however, the units oi the shillings digitis odd, the relay '8 will be energized, and the contacts l82 closed, so that the circuit will continue through a line ill, the emitter EM. at the "live time in the cycle, and the third lowest accumulator-magnet IIIMC. In this manner nothing will be entered with even shillings and no pence, while 5 will be entered with odd'shillings and no pence.

When the relay ID is energized. the entering circuit will extend from the cam contacts FC-ll through the contacts lD-I, and lD--2. the line ill, the contacts lD-4, a line I" and .then through contacts ES-2 closed if the relay E8 is energized, a line I", the emitter EM! at the "one" time in the cycle, and-jthe third multiplicand accumulator-magnet illMC. If the relay IS had been energized, the circuit would have continued from the line I" through the contacts lS-l, a line I and the emitter EMU at the "six" time in the cycle. Thus, 1 or 6 is entered depending upon whether the units of shillings were even or odd respectively.

With the relay D energized, the circuit extends through the contacts ID! and CD-J. the line ill and either the contacts 128-4 and the emitter EMS at the two" time in the cycle, or through the contacts 08-! and the emitter EM. at the "seven time in the cycle. Finally, with the relay 9D energized, the circuit extends through the contacts ID2, lD-2, ID-! and SD-i, the line ill. a line i" and either the contacts ES-3 or 'lS-l. In the former case the circuit is established at the "three" time in the cycle and in the latter case at the "eight" time in the cycle.

Turning again to Table II, it will be noticed that nothing should be entered into the tenths denomination of the multlplicand register MC, when the units 01' shillings value is or 1, assuming the tens oi shillings be zero but that 5 must be entered when the units of shillings is 0 or 1 and the tens of shillings is 1. In the same way there are two values to be entered for each pair 01' units of shillings digits, according to the value oi the tens of shillings digit. Thus, 3 must be entered when the units of shillings is 6 or '1 and the tens of shillings zero, but 8 must be en-' while the two corresponding hole positions are passing the units of shillings brush. Thus the relay appropriate to the unit of shillings digit will be energized, and will hold itsel! energised through its No. 1 contacts, and the cam contacts -28.

v The tens oi shillings brush is included in a circuit which comprises cam-contacts I'C-I'l (which close while the "one" hole is passing the tens of shillings brush) and relays "8. Thus, these relays will be energized ii there is 10s. in the amount but not ii the tens oi shillings digit is zero. In the example discussed previously, the shillings amount was 17s., and accordingly the relays IIS and 0-18 will be energized, and will maintain themselves energized until towards the end of the card-reading cycle.

. From Table II it will be seen that 8 should be entered into the tenths of pounds" denomination in the multlplicand register when the shillings amount is'l'l. The relay 8-18 closes contacts 6-18-2, while the relay IIS opens its normally closed contacts "8-! and closes its normally open contacts "8-3. When the brush of the emitter EM'I engages the "eight" digital segment, a circuit is completed through the cam contacts FC-Sl, a line I, the contacts $'I8-I,

the contacts IDS-I, a line I, the emitter EMI, and the fourth accumulator-magnet HIMC' of the multlplicand register. It the shillings had been 7s., the relay contacts "8-4 would have been clomd, and the relay contacts IDS-I open, since the relay IIS would not be energized. The circuit would then have extended through the contacts 8-18-2 and Ids-2, a line I", and the "three digital segment of the emitter EM'I, so that 3 would have been entered in the multiplicand register. The circuit for entering the decimal equivalent of other shillings amounts can readily be traced. It'should be noted that while the 9 hole is sensed before the 10 hole, the circults are not efl'ective until a later cycle and after the 10 hole has been sensed to control the contacts lllS--2, IDS-4 and preset the same before entering operations take place under control or the emitters. Thus FUJI which supplies current to these contacts is not closed until the second half of the card teed cycle and after the card has been completely sensed.

At this stage the card has been completely read, and the multiplier has been registered in the register MPand the multlplicand has been decimalized and registered in the register MC, while the remainder has. been registered in the relays. DC and RC. The machine is now ready to commence its multiplication, but,bei.'ore doing so, the accumulators LH and MP are reset in the following manner.

At the end of the last run of cards, the machine is stopped with the second card-feed rack in the last column position in which a card carried by' it is in position for ejection. In this position the rack closes the contacts P2 (Figure 3h). These contacts complete a circuit through a relay K which opens the contacts K-i and closes the contacts K-I. This relay also closes contacts K-! (Figure 3a). At the end of the card-feeding cycle, the first card is passed into the punching mechanism and closes cardlever contacts I (Figures 2 and 3h) so as to energize a relay F. The coil F closes contacts F-3 (Figure 3a) and at the end of the cardi'eeding cycle a circuit is completed from the AC line I82, through cam-contacts CC--2, the relay contacts K-3, relay contacts L--2 which are normally closed, the relay contacts F3, and the 

